1. Field of the Invention
The present invention relates to a card edge connector for an electronic card, and more particularly, to a card edge connector wherein a low or zero insertion force is applied to the electronic card when the electrical card is inserted into the card edge connector.
2. Description of the Prior Art
U.S. Pat. No. 4,553,804 issued to Scott et al. on Nov. 19, 1985, discloses a related conventional card edge connector. The card edge connector comprises an elongated outer housing having a channel extending in a longitudinal direction, a plurality of contacts mounted on said outer housing on either side of said channel, said contacts having lower end portions projecting exteriorly of said outer housing through the bottom of said channel, and upper portions interior said outer housing adapted to contact opposite sides of a circuit board, an inner housing mounted interior said outer housing for movement inwardly and outwardly along a vertical direction normal to the longitudinal direction, an ovally shaped cam having an axis of rotation extending in the longitudinal direction, said cam being adapted to be rotated from a first position presenting a narrow cross section in the vertical direction to a second position presenting a wider cross section in the vertical direction, a pair of first cam engaging surfaces and a pair of second cam engaging surfaces, said inner and outer housings each including respective first and second cam engaging surfaces, said first surfaces being diametrically opposed along the vertical direction and adapted to be moved apart when said cam is rotated from said first position, said second surfaces being laterally displaced from said first surfaces along the direction of rotation of said cam and adapted to be moved apart when said cam is rotated from said second position, said inner housing including means adapted to engage and urge upper portions of said contacts apart when said cam is rotated from one of said positions to the other of said positions whereby removal or insertion of a circuit board is permitted.
However, when the cam is rotated from one of the positions to the other of the positions, a force is applied to the inner housing which may cause imbalance of the inner housing. Furthermore, there is no sealing protection for contact mating portions of the contacts when PCB is not installed.
Hence, an improved card edge connector is needed to solve the above problems.